Note: Descriptions are shown in the official language in which they were submitted.
43321CAN4A
133819~
ENERGY CURABLE COMPOSITIONS : TWO COMPONENT CURING AGENTS
Field of the Invention
This invention relates to an energy-
polymerizable composition comprising an ethylenically-
unsaturated monomer optionally in combination with
polyurethane precursors or an epoxy monomer, or an epoxy
monomer, or polyurethane precursors, and as curing agent a
combination of an organometallic salt and an onium salt and
a method therefor. In another aspect, cured articles
comprising the compositions of the invention are disclosed.
The compositions are useful, for example, as protective
coatings, binders for magnetic media or abrasives,
adhesives, and in graphic arts applications.
Background Of The Invention
Various polymeric coatings and articles are
produced in processes involving the use of organic
solvents. There is an intense effort by law makers,
researchers, and industry to promote high and 100% solids
formulations to reduce or eliminate the use of such
solvents and the attendent costs and environmental
contamination. These processes require a latent catalyst
or latent reaction promoter which can be activated in a
controlled fashion.
Thermal curing of polyurethane precursors using
reaction promotors such as tin salts and tertiary amines is
known in the art. Curing of polymerizable mixtures of
polyisocyanates with polyols (referred to as polyurethane
precursors) using thermally latent catalysts is known in
the art (see for example U. S. Patent Nos. 4,521,545, and
4,582,861).
-2- 1338194
Photocuring of urethane (meth)acrylates is well
known (see T. A. Speckhard, K.K.S. Hwang, S.B. Lin, S.Y.
Tsay, M. Koshiba, Y.S. Ding, S.L. Cooper J. Appl. Polymer
Science, 1985, 30, 647-666. C. Bluestein Polym.-Plast.
Technol. Eng. 1981, 17 83-93). Photocuring of polyurethane
precursors using diazonium salts, tertiary amine
precursors, and organotin compounds is also known (see U.S.
Patent Nos. 4,544,466, 4,549,945, and EP 28,696, Derwent
abstract). All of these methods suffer from one or more of
the following disadvantages: sensitivity to oxygen,
requirement of ultraviolet and/or high intensity light, the
need for modified resins, loss or dilution of urethane
properties, low activity, poor solubility, and poor
potlife.
The prior art discloses processes for the
polymerization of epoxy materials. It is further known
that a metallocene, such as ferrocene, can be used as a
curing accelerator for epoxy materials (U.S. Patent No.
3,705,129). U.S. Patent Nos. 3,709,861, 3,714,006,
3,867,354 and 4,237,242 relate to the use of transition
metal complexes in the reaction between polyepoxides and
polyfunctional curing additives, but they do not teach the
polymerization of epoxide group-containing compositions not
containing a curing additive. The polymerization of
epoxide group-containing materials is also known. Among
such processes are those in which the polymerization
catalyst is a radiation-sensitive onium salt of a Lewis
acid (e.g. diazonium salts as is described in U.S. Patent
No. 3,794,576 and U.S. Patent No. 4,080,274; halonium salts
as is disclosed in U.S. Patent No. 4,026,705; and the onium
salts of Group VIA elements, particularly the sulfonium
salts, as are disclosed in U.S. Patent No. 4,058,400), or a
dicarbonyl chelate compound of a Group IIIA-VA element as
is disclosed in U.S. Patent No. 4,086,091. These
compositions are limited to ultraviolet radiation for
polymerization. Furthermore, the dicarbonyl chelates are
moisture sensitive.
_ ~3~ 133819~
U.S. Patent No. 4,216,288 teaches the thermal
curing of cationally polymerizable compositions using onium
salts and reducing agents.
Energy polymerizable compositions comprising
ionic salts of organometallic complex cations and
cationically sensitive materials and the curing thereof has
been taught (see European Patent Document Nos. 109,851;
094,914, Derwent abstract; and 094,915, Derwent abstract).
Neutral organometallic compounds have been used
in combination with neutral halogenated compounds for the
photocuring of ethylenically-unsaturated monomers. (G.
Smets, Pure G. Appl. Chem., 53, 611,615 (1981);
H.M. Wagner, M.D. Purbrick, J. Photograph Science, 29,
230-235 (1981).
The use of certain photosensitizers with onium
salts for initiation of polymerization of ethylenically-
unsaturated monomers is also well known in the art. This
technique has found applications in printing, duplication,
copying, and other imaging systems (see J. Kosar in Light
Sensitive Systems: Chemistry and Application of Nonsilver
Halide Photographic Processes, Wiley, New York, 1965, pp
158-193). Aryliodonium salts have been previously
described for use as photoinitiators in addition-
polymerizable compositions. (See U.S. Patent Nos.
3,729,313, 3,741,769, 3,808,006, 4,228,232, 4,250,053 and
4,428,807; H. J. Timpe and H. Baumann, Wiss Z. Tech.
Hochsch. Leuna-Merseburg, 26, 439 (1984); H. saumann, s.
Strehmel, H.J. Timpe and U. Lammel, J. Prakt. Chem., 326
(3), 415 (1984); and H. Baumann, U. Oertel and H.J. Timpe,
Euro. Polym. J., 22 (4), 313 (April 3, 1986).
Radiation dual curable compositions containing
ethylenically unsaturated monomers and epoxy monomers have
been described in U.S. Patent Nos. 4,156,035, 4,227,978,
and 4,623,676. These compositions include onium salts
combined with organic compounds as the curing agent, but do
not contain any organometall=ic compounds.
The dual curing of acrylate/polyurethane
precursor mixtures is known but these curing methods are
~4~ 1~ 38194
not entirely photoactivated nor are any methods known that
provide for the simultaneous curing of the polyurethane
precursors and acrylates ~see U.S. Patent No. 4,432,793 and
Roesler, Modern Paint and Coatings, April, 1986, pages
46-55)-
U.S. Patent No. 4,677,137 teaches the use of one
of a supported onium salt or an ionic salt of
organometallic complex as an initiator of the
polymerization of cationically polymerizable materials.
The reference does not teach the combination of an ionic
salt of an organometallic complex and an onium salt as
photoinitiators.
U.S. Patent No. 4,740,577 and EPO 0 250 364
- teach the use of an ionic salt of an organometallic complex
combined with polyurethane precursors in an energy
polymerizable composition. The references do not disclose
the use of an onium salt with the ionic salt of an
organometallic complex for curing polyurethane precursors.
U.S. Patent No. 4,707,432 teaches a free
radically polymerizable composition comprising a free
radically polymerizable material and a photoinitiator
system comprising an alpha-cleavage or homolytic bond
cleavage photoinitiator and a ferrocenium salt. The
reference does not teach the combination of an onium salt
with the ionic salt of an organometallic complex. They
teach specifically that the free radical initiator is not
an onium compound.
EP 126712 and EP 152377 (Derwent Abstracts)
disclose hardenable composition contain a radical and/or
cationically polymerizable material, or their mixtures and
at least one ferrous-aromatic complex compound and at least
one electron-acceptor as oxidising agent. Onium salts are
not disclosed.
GB 2191199A, published December 9, 1987, teaches
the combination of an onium salt with the ionic salt of an
organometallic complex for polymerization of compositions
by irradiating at two different wavelengths. The reference
does not teach the simultaneous initiation of the
- 1 3 3 8 1 9 4 60557-3623
polymerization of two different polymerizable materials nor do
they demonstrate the enhanced thermal stability derived from
this composition. The reference does not teach the polymerization
of polyurethane precursors, nor does it teach that such
compositions cure faster and have increased stability.
Summary of the Invention
Briefly, the present invention provides an energy
polymerizable composition comprising one of 1) at least one
ethylenically-unsaturated monomer, and, optionally, one of poly-
urethane precursors or epoxy monomers, or 2) at least one epoxymonomer, or 3) polyurethane precursors, and as curing agent a
combination of an organometallic salt ~ionic salt of an organo-
metallic complex cation) and an onium salt. The compositions are
useful as protective and decorative coatings, inks, adhesives,
in restorative and sealant applications, and in imaging applica-
tions.
According to one aspect of the present invention there
is provided a method comprising the steps of: a) providing a
mixture comprising (1) only one polymeric precursor composition
selected from the groups consisting of (a) polyurethane
precursors, (b) at least one epoxy monomer, and (c) at least one
ethylenically-unsaturated monomer and polyurethane precursors,
and (2) a catalytically-effective amount of a two-component curing
agent comprising (a) an organometallic salt, and (b) an onium
salt, and, optionally, an effective amount of photosensitizer, and
b) allowing said mixture to polymerize or adding energy to said
mixture to effect polymerization.
A
1 3 3 8 1 9 4 60557-3623
According to a further aspect of the present invention
there is provided a polymerizable composition comprising the
polymeric precursor selected from one of the groups consisting of
(1) at least one epoxy monomer, (2) polyurethane precursors, and
(3) at least one ethylenically-unsaturated monomer and poly-
urethane precursors, and a two-component curing agent comprising
an organometallic salt and an onium salt.
According to another aspect of the present invention
there is provided a graphic arts construction comprising a poly-
merizable composition comprising a polymeric precursor selectedfrom the group consisting of (1) polyurethane precursors, (2) at
least one ethylenically-unsaturated monomer and polyurethane
precursors, and (3) at least one epoxy monomer, and a two-
component curing agent comprising an organometallic salt and an
onium salt.
According to a still further aspect of the present
invention there is provided a binder for a magnetic medium or an
abrasive comprising a polymerizable composition comprising a
polymeric precursor selected from the group consisting of (1) at
least one ethylenically-unsaturated monomer, (2) polyurethane
precursors, (3) at least one epoxy monomer, (4) at least one
ethylenically-unsaturated monomer and polyurethane precursors,
and (5) at least one ethylenically-unsaturated monomer and at
least one epoxy monomer, and a two-component curing agent
comprising an organometallic salt and an onium salt.
According to another aspect of the present invention
there is provided an article comprising a protective coating on
A~
~ -5b-
- 1338194 60557-3623
a substrate wherein said protective coating is a polymerizable
composition comprising a polymeric precursor selected from the
group consisting of (1) polyurethane precursors, (2) at least
one epoxy monomer, (3) at least one ethylenically-unsaturated
monomer and polyurethane precursors, and (4) at least one
ethylenically-unsaturated monomer and at least one epoxy monomer,
and a two-component curing agent comprising an organometallic
salt and an onium salt.
When two polymerizable components are present they can
be present in any proportion, preferably in the range of 0.1:99.9
to 99.9:0.1 part by weight, more preferably 1:99 to 99:1 part by
weight, and most preferably 2:98 to 98:2 parts by weight.
What is not taught in the prior art, but what is taught
in this invention, is the use of organometallic salts in combina-
tion with onium salts for the simultaneous photo- or accelerated
particle-induced (electron beam-induced) or thermal curing of
ethylenically-unsaturated monomers alone or in combination with
polyurethane precursors or epoxy monomers, or epoxy monomers, or
polyurethane precursors, when two different polymerizable
materials are present, the instant invention composition and
method relies on the simultaneous initiation of the polymerization
of both materials. Only one irradiation step is utilized.
Advantages of compositions of the present invention when
utilized in 100% reactive coating compositions include:
,A '~
~;
-6- 1~819~
An industrial process innovation is disclosed
that will reduce, minimize, or eliminate the
generation of industrial solvent waste while reducing
energy consumption.
Radiation processing, particularly utilizing
electron beam and photogenerated catalysts, has
potential capability for penetrating and polymerizing
thick and pigmented coatings.
More readily available monomers can be used in
place of functionalized oligomers (used in the prior
art) thereby resulting in lower viscosity monomer
solutions which are easier to coat than more viscous
oligomer solutions.
Expanding the scope of curable monomers to
include polyisocyanates/polyols and epoxides allows
increased flexibility in designing coatings with
specific properties.
The combination photoinitiators provides
increased thermal stability in combination with
increased rate of cure.
In this application:
"energy-induced curing" means curing by means of
at least one of electromagnetic radiation (ultraviolet and
visible) accelerated particles (including electron beam),
and thermal (infrared and heat) means;
"ethylenically-unsaturated monomer" means those
monomers that polymerize by a free-radical mechanism;
"catalytically-effective amount" means a
quantity sufficient to effect polymerization of the curable
composition to a polymerized product at least to a degree
to cause an increase in the viscosity of the composition;
"organometallic salt" means one or more ionic
salts of organometallic complex cations wherein the cations
contain at least one carbon atom of an organic group bonded
to a metal atom ("Basic Inorganic Chemistry", F.A. Cotton,
G. Wilkinson, Wiley, New York, 1976, p. 497);
` ~ _7_ 1338194
"polyurethane precursors" means a mixture of one
or more monomers of the type including diisocyanates and
polyisocyanates, and one or more monomers of the type
including diols and polyols. Compounds bearing at least
two isocyanate-reactive hydrogen atoms may be substituted
for diols and polyols; the ratio of isocyanate groups to
isocyanate-reactive hydrogen atoms is 1:2 to 2:1;
"bridging ligand" means a ligand that bonds to
two or more metals in the presence or absence of
metal-metal bonds;
"polyisocyanate" means an aliphatic or aromatic
isocyanate having 2 or more isocyanate groups;
"polyol" means an aliphatic or aromatic compound
containing 2 or more hydroxyl groups;
"onium salt" means one or more salts of cationic
compounds such as diazonium, halonium, and hypervalent
Group VIA elements; and
"bireactive monomer" means a monomer which
contains an ethylenically unsaturated group and at least
one of an epoxy, an isocyanate, and an isocyanate-reactive
group.
Detailed Disclosure of the Invention
The present invention provides a photo and/or
thermally polymerizable composition comprising one of 1) at
least one ethylenically-unsaturated monomer optionally in
combination with at least one of polyurethane precursors or
at least one epoxy monomer, or 2) at least one epoxy
monomer, or 3) polyurethane precursors, and a bic4cmponent
B 30 curing agent therefore, the bicomponent curingPagent~l~n~all
ca~c6 comprising
` ~ -8- 133819~
1) an organometallic salt having the structure
[((L )(L2)M) (L3)(L4)]+- X
wherein
M represents a metal atom selected from the
elements of Periodic Groups IVB, VB, VIB, VIIB, and VIIIB;
with the proviso that formula I represents an
organometallic salt having a mono- or bimetallic cation;
Ll represents none, 1, 2, or 3 ligands
contributing pi-electrons that can be the same or different
ligand selected from substituted and unsubstituted acyclic
and cyclic unsaturated compounds and groups and substituted
-and unsubstituted carbocyclic aromatic and heterocyclic
aromatic compounds, each capable of contributing two to
twelve pi-electrons to the valence shell of M;
L2 represents none, or 1 to 6 ligands
contributing an even number of sigma-electrons that can be
the same or different selected from mono-, di-, and
tri-dentate ligands, each donating 2, 4, or 6
sigma-electrons to the valence shell of M;
L3 represents none, 1 or 2 bridging ligands
contributing pi-electrons that can be the same or different
ligand selected from substituted and unsubstituted acyclic
and cyclic unsaturated compounds and groups and substituted
and unsubstituted carbocyclic aromatic and heterocyclic
aromatic compounds, each capable of acting as a bridging
ligand contributing 4 to 24 pi-electrons to the valence
shells of two metal atoms M, simultaneously;
L4 represents none, 1, 2, or 3 bridging ligands
contributing an even number of sigma-electrons that can be
the same or different selected from mono-, di-, and
tri-dentate ligands, each donating 2, 4 or 6
sigma-electrons to the valence shells of two metal atoms M,
simultaneously; with the proviso that the total electronic
=- charge contributed to M by the ligands Ll, L2, L3, and L4
plus the product of the ionic charge on M with b results in
a residual positive charge of e to the cation;
1~38194
-
g
b ls an lnteger havlng a value of 1 or 2;
e ls an lnteger havlng a value of 1 or 2, the
resldual electrlcal charge of the catlon;
X ls an anlon selected from organlc sulfonate anlons
and halogen-contalnlng complex anlons of a metal or metallold;
f ls an lnteger of 1 or 2, the number of anlons
requlred to neutrallze the posltlve charge e on the catlon;
and
2) an onlum salt oxldlzlng agent havlng the structure:
AY III
whereln
A ls an organlc catlon selected from those descrlbed
ln U.S. Patent Nos. 3,708,296, 3,72g,313, 3,741,769,
3,794,576, 3,808,006, 4,026,705, 4,058,401, 4,069,055,
4,101,513, 4,216,288, 4,394,403, and 4,623,676, preferably
selected from dlazonium, lodonlum, and sulfonlum catlons, more
preferably A ls selected from dlphenyllodonlum,
trlphenylsulfonlum and phenylthlophenyl dlphenylsulfonlum; and
Y ls an anlon, the counterlon of the onlum salts
lncludlng those ln whlch Y ls an organlc sulfonate, or
halogenated metal or metallold, such as CH3SO3 , CF3SO3 ,
C6H5SO3 , p-toluenesulfonate, p-chlorobenzenesulfonate and
related lsomers and the llke, and those ln whlch Y has the
formula DZr~ whereln D ls a metal from Groups IB to VIIIB or a
metal or metallold from Groups IIIA to VA of the Perlodlc
Chart of Elements, Z ls a halogen atom or hydroxy group, and r
ls an lnteger havlng a value of 1 to 6. Preferably, the
metals are copper, zlnc, tltanlum, vanadlum, chromlum,
manganese, lron, cobalt, or nlckel and the metallolds
preferably are boron, alumlnum, antlmony, tln, arsenlc, and
phosphorus. Preferably, the halogen, Z, ls chlorlne or
fluorlne. Illustratlve of sultable anlons
60557-3623
-lo- 133819~
are BF4 , PF6, AsF6, SbF6, FeCl4, SnCl5, SbFs, AlF6,
GaCl4~, InF4 , TiF6 , etc. Preferably, the anions are
CF3 S03 , BF4 , PF6 , SbF6 , SbF50H , AsF6 , and SbCl6 .
In a preferred composition of the invention, the
salts of the organometallic complex cation have the
formula:
[(L5)(L6)M]+- X II
wherein
M represents a metal atom selected from elements
of the Period Groups IVB, VB, VIB, VIIB, and VIIIB;
L5 represents none, one or two ligands that can
be the same or different, contributing pi-electrons
selected from the same groups of ligands from which ligand
L of formula I is selected;
L6 represents none or 1 to 6 ligands that can be
the same or different, contributing an even number of
sigma-electrons selected from the same group of ligands
from which ligand L2 of formula I is selected;
with the proviso that the total electronic charge
contributed to M by L5 and L6 plus the ionic charge on M
results in a residual net positive charge of e to the
complex; and e, f, and X have the same definition as given
in formula I.
Salts of organometallic complex cations having
formulae I and II are radiation sensitive in addition to
being thermally sensitive or they can be cured in a two
stage curing process using radiation followed by heat.
Ligands L1 to L6 are well known in the art of
transition metal organometallic compounds.
Ligand Ll of general formula I and ligand L~ of
general formula II are provided by any monomeric or
polymeric compound having an accessible unsaturated group,
i.e., an ethylenic, -C=C- group; acetylenic, -C-C- group;
or aromatic group which have accessible pi-electrons
regardless of the total molecular weight of the compound.
By "accessible", it is meant that the compound (or
- -11- 133819 1
precursor compound from which the accessible compound is
prepared) bearing the unsaturated group is soluble in a
reaction medium, such as an alcohol, e.g., methanol; a
ketone, e.g., methyl ethyl ketone; an ester, e.g., amyl
acetate; a halocarbon, e.g., trichloroethylene; an alkane,
e.g., decalin; an aromatic hydrocarbon, e.g., anisole; an
ether, e.g., tetrahydrofuran; etc, or that the compound is
divisible into very fine particles of high surface area so
that the unsaturated group (including aromatic group) is
sufficiently close to a metal atom to form a pi-bond
between that unsaturated group and the metal atom. By
polymeric compound, is meant, as explained below, that the
ligand can be a group on a polymeric chain.
Illustrative of ligands Ll and L5 are the linear
and cyclic olefinic and acetylenic compounds having less
than lO0 carbon atoms, preferably having less than 60
carbon atoms, and from zero to 10 hetero atoms selected
from nitrogen, sulfur, non-peroxidic oxygen, arsenic,
phosphorus, selenium, boron, antimony, tellurium, silicon,
germanium, and tin, such as, for example, ethylene,
acetylene, propylene, methylacetylene, 1-butene, 2-butene,
diacetylene, butadiene, 1,2-dimethylacetylene, cyclobutene,
pentene, cyclopentene, hexene, cyclohexene,
1,3-cyclohexadiene, cyclopentadiene, 1,4-cyclohexadiene,
cycloheptene, l-octene, 4-octene, 3,4-dimethyl-3-hexene,
and l-decene; eta3-allyl, eta3-pentenyl, norbornadiene,
eta5-cyclohexadienyl, eta6-cycloheptatriene,
eta3-cyclooctatetraene, and substituted and unsubstituted
carbocyclic and heterocyclic aromatic ligands having up to
25 rings and up to lO0 carbon atoms and up to lO hetero
atoms selected from nitrogen, sulfur, non-peroxidic oxygen,
phosphorus, arsenic, selenium, boron, antimony, tellurium,
silicon, germanium, and tin, such as, for example,
eta5-cyclopentadienyl, eta6-benzene, eta6-mesitylene, eta6-
hexamethylbenzene, eta6-fluorene, eta6-naphthalene, eta6-
anthracene, eta6-chrysene, eta6-pyrene, eta7-
cycloheptatrienyl, eta6-triphenylmethane, etal 2 _
paracyclophane, eta1 2 -1, 4-diphenylbutane, eta5-pyrrole,
`~ -12- 1338194
eta5-thiophene, eta5-furan, eta6-pyridine, eta6-gamma-
picoline, eta6-quinaldine, eta6-benzopyran,
eta6-thiochrome, eta6-benzoxazine, eta6-indole,
eta6-acridine, eta6-carbazole, eta6-triphenylene,
eta6-silabenzene, eta6-arsabenzene, eta6-stibabenzene,
eta6-2,4,6-triphenylphosphabenzene, eta5-selenophene, eta6-
dibenzostannepine, eta5-tellurophene, eta6-phenothiarsine,
eta6-selenanthrene, eta6-phenoxaphosphine,
eta6-phenarsazine, eta6-phenatellurazine, and
eta6-l-phenylborabenzene. Other suitable aromatic
compounds can be found by consulting any of many chemical
handbooks.
As mentioned before, the ligand can be a unit of
a polymer, for example, the phenyl group in polystyrene,
poly(styrene-co-butadiene), poly(styrene-co-methyl
methacrylate), poly(alpha-methylstyrene),
polyvinylcarbazole, and polymethylphenylsiloxane; the
cyclopentadiene group in poly(vinylcyclopentadiene); the
pyridine group in poly(vinylpyridine), etc. Polymers
having a weight average molecular weight up to 1,000,000 or
more can be used. It is preferable that 5 to 50 percent of
the unsaturated or aromatic groups present in the polymer
be complexed with metallic cations.
Each of the ligands L1 and L5 can be substituted
by groups that do not interfere with the complexing of the
ligand with the metal atom or which do not reduce the
solubility of the ligand to the extent that complexing with
the metal atom does not take place. Examples of
substituting groups, all of which preferably have less than
30 carbon atoms and up to 10 hetero atoms selected from
nitrogen, sulfur, non-peroxidic oxygen, phosphorus,
arsenic, selenium, antimony, tellurium, silicon, germanium,
tin, and boron, include hydrocarbyl groups such as methyl,
ethyl, butyl, dodecyl, tetracosanyl, phenyl, benzyl, allyl,
benzylidene, ethenyl, and ethynyl; hydrocarbyloxy groups
~- such as methoxy, butoxy, and phenoxy; hydrocarbylmercapto
groups such as methylmercapto (thiomethoxy), phenylmercapto
(thiophenoxy); hydrocarbyloxycarbonyl such as
-13- 1338194
methoxycarbonyl and phenoxycarbonyl; hydrocarbylcarbonyl
such as formyl, acetyl, and benzoyl; hydrocarbylcarbonyloxy
such as acetoxy, benzoxy, and cyclohexanecarbonyloxy;
hydrocarbylcarbonamido, e.g., acetamido, benzamido; azo,
boryl; halo, e.g., chloro, iodo, bromo, and fluoro;
hydroxy; cyano; nitro; nitroso, oxo; dimethylamino;
diphenylphosphino, diphenylarsino; diphenylstibine;
trimethylgermane; tributyltin; methylseleno; ethyltelluro;
and trimethylsiloxy; condensed rings such as benzo,
cyclopenta; naphtho, indeno; and the like.
Ligands L2 in formula I, and L6 in formula II are
provided by monodentate and polydentate compounds
preferably containing up to about 30 carbon atoms and up to
lO hetero atoms selected from nitrogen, sulfur, non-
peroxidic oxygen, phosphorus, arsenic, selenium, antimony,
and tellurium, upon addition to the metal atom, followingloss of zero, one, or two hydrogens, the polydentate
compounds preferably forming with the metal, M, a 4-, 5-,
or 6-membered saturated or unsaturated ring. Examples of
suitable monodentate compounds or groups are carbon
monoxide, carbon sulfide, carbon selenide, carbon
telluride, alcohols such as ethanol, butanol, and phenol;
nitrosonium (i.e., NO+); compounds of Group VA elements
such as ammonia, phosphine, trimethylamine,
trimethylphosphine, triphenylamine, triphenylphosphine,
triphenylarsine, triphenylstibine, tributylphosphite,
isonitriles such as phenylisonitrile, butylisonitrile;
carbene groups such as ethoxymethylcarbene,
dithiomethoxycarbene; alkylidenes such as methylidene,
ethylidene; suitable polydentate compounds or groups
include 1,2-bis(diphenylphosphino)ethane, 1,2-
bis(diphenylarsino)ethane, bis(diphenylphosphino)methane,
ethylenediamine, propylenediamine, diethylenetriamine, 1,3-
diisocyanopropane, and hydridotripyrrazolyborate; the
hydroxycarboxylic acids such as glycolic acid, lactic acid,
salicylic acid; polyhydric phenols such as catechol and
2,2'-dihydroxybiphenyl; hydroxyamines such as ethanolamine,
propanolamine, and 2-aminophenol; dithiocarbamates such as
-14- 1338194
diethyldithiocarbamate, dibenzyldithiocarbamate; xanthates
such as ethyl xanthate, phenyl xanthate; the dithiolenes
such as bis(perfluoromethyl)-1,2-dithiolene;
aminocarboxylic acids such as alanine, glycine and
o-aminobenzoic acid; dicarboxylic diamines as oxalamide,
biuret; diketones such as 2,4-pentanedione; hydroxyketones
such as 2-hydroxyacetophenone; alpha-hydroxyoximes such as
salicylaldoxime; ketoximes such as benzil oxime; and
glyoximes such as dimethylglyoxime. Other suitable groups
are the inorganic groups such as, for example, CN , SCN ,
F , OH , Cl , Br , I , and H and the organic groups such
as, for example, acetoxy, formyloxy, benzoyloxy, etc. As
mentioned before, the ligand can be a unit of a polymer,
for example the amino group in poly(ethyleneamine); the
phosphino group in poly(4-vinylphenyldiphenylphosphine);
the carboxylic acid group in poly(acrylic acid); and the
isonitrile group in poly(4-vinylphenylisonitrile).
Ligand L3 in ~ormula I is provided by any
monomeric or polymeric compound having an accessible
unsaturated group, such as an ethylenic group -C=C- or
acetylenic -C=C- group or an aromatic group which have
accessible pi-electrons regardless of the total molecular
weight of the compound.
Illustrative of ligand L3 are the linear and
cyclic diene and acetylenic compounds preferably having
less than 60 carbon atoms and up to 10 hetero atoms
selected from nitrogen, sulfur, non-peroxidic oxygen,
phosphorus, arsenic, selenium, boron, antimony, tellurium,
silicon, germanium, and tin, such as for example,
acetylene, methylacetylene, diacetylene, butadiene,
1,2-dimethylacetylene, 1,3- cyclohexadiene,
cyclopentadiene, and 1,4-cyclohexadiene; eta3-allyl,
eta3-pentenyl, norbornadiene, eta5-cyclohexadienyl,
eta6-cycloheptatriene, eta3-cyclooctatetraene, and
substitued and unsubstituted carbocyclic and heterocylic
=- aromatic ligands having up to 25 rings and up to 100 carbon
atoms and up to 10 hetero atoms selected from nitrogen,
sulfur, non-peroxidic oxygen, phosphorus, arsenic,
-15- 133 8 19 4
selenium, boron, antimony, tellurium, silicon, germanium,
and tin, such as, for example, eta5-cyclopentadienyl,
eta6-benzene, eta6-mesitylene, eta6-hexamethylbenzene,
eta6-fluorene, eta6-naphthalene, eta6-anthracene,
eta6-chrysene, eta6-pyrene, eta7-cycloheptatrienyl,
eta6-triphenylmethane, eta5-pyrrole, eta5-thiophene,
eta5-furan, eta6-pyridine, eta6-gamma-picoline,
eta6-quinaldine, eta6-benzopyran, eta6-thiochrome, eta6-
benzoxazine, eta6-indole, eta6-acridine, eta6-carbazole,
eta6~1,2,3,4,4a,12a)-eta6-(7,8,9,10,1Oa,lOb)chrysene,
eta6-triphenylene, eta6,eta6 -paracyclophane,
eta6,eta6 -1,4-diphenylbutane, eta6-silabenzene,
eta6-arsabenzene, eta6-stibabenzene, eta6-2,4,6-
triphenylphosphabenzene, eta5-selenophene, eta6-
dibenzostannepine, eta5-tellurophene, eta6-phenothiarsine,
eta6-selenanthrene, eta6-phenoxaphosphine, eta6-
phenarsazine, eta6-phenatellurazine, and eta6-l-
phenylborabenzene. Other suitable aromatic compounds can
be found by consulting any of many chemical handbooks.
Each of the ligands L3 can be substituted by
groups that do not interfere with the complexing of the
ligand with the metal atom or which do not reduce the
solubility of the ligand to the extent that complexing with
the metal atom does not take place. Examples of
substituting groups, all of which preferably have less than
30 carbon atoms and zero to 10 hetero atoms selected from
nitrogen, sulfur, non-peroxidic oxygen, phosphorus,
arsenic, selenium, antimony, tellurium, silicon, germanium,
tin, and boron, include hydrocarbyl groups such as methyl,
ethyl, butyl, dodecyl, tetracosanyl, phenyl, benzyl, allyl,
benzylidene, ethenyl, and ethynyl; hydrocarbyloxy groups
such as methoxy, butoxy, and phenoxy; hydrocarbylmercapto
groups such as methylmercapto (thiomethoxy), phenylmercapto
(thiophenoxy); hydrocarbyloxycarbonyl such as
methoxycarbonyl and phenoxycarbonyl; hydrocarbylcarbonyl
such as formyl, acetyl, and benzoyl; hydrocarbylcarbonyloxy
such as acetoxy, benzoxy, and cyclohexanecarbonyloxy;
hydrocarbylcarbonamido, e.g., acetamido, benzamido; azo;
-16- 133819~
boryl; halo, e.g., chloro, iodo, bromo, and fluoro,
hydroxy; cyano; nitro; nitroso, oxo; dimethylamino,
diphenylphosphino, diphenylstibine; trimethylgermane;
tributyltin; methylseleno; ethyltelluro; and
trimethylsiloxy; condensed rings such as benzo, cyclopenta;
naphtho, indeno; and the like.
Ligand L4 is provided by monodentate and
polydentate compounds preferably containing up to about 30
carbon atoms and zero to 10 hetero atoms selected from
nitrogen, sulfur, non-peroxidic oxygen, phosphorus,
arsenic, selenium, antimony, and tellurium. Examples of
suitable mondentate compounds or groups are carbon
monoxide, carbon sulfide, carbon selenide, carbon
telluride, alcohols such as ethanol, butanol, and phenol;
nitrosonium (i.e., NO+); compounds of Group VA elements
such as triphenylamine, triphenylphosphine,
triphenylarsine, triphenylstibine, isonitriles such as
phenylisonitrile; suitable polydentate compounds or groups
include 1,2-bis(diphenylphosphino)-ethane,
1,2-bis(diphenylarsino)ethane,
bis(diphenylphosphino)methane, ethylenediamine,
propylenediamine, diethylenetriamine,
1,3-diisocyanopropane, and hydridotripyrazolylborate; the
hydroxycarboxylic acids such as glycolic acid, lactic acid,
salicyclic acid; polyhydric phenols such as catechol and
2,2'-dihydroxybiphenyl; hydroxyamines such as ethanolamine,
propanolamine, and 2-aminophenol; dithiocarbamates such as
diethyldithiocarbamate, dibenzyldithiocarbamate; xanthates
such as bis(perfluoromethyl)-1,2-dithiolene;
aminocarboxylic acids such as alanine, glycine and
o-aminobenzoic acid; dicarboxylic diamides such as
oxalamide, biuret; diketones such as 2,4-pentanedione;
hydroxyketones such as 2-hydroxyacetophenone;
alpha-hydroxyoximes such as salicylaldoxime; ketoximes such
as benzil oxime; and glyoximes such as dimethylglyoxime.
= Other suitable groups are the inorganic groups such as, for
example, CN , SCN , F , OH , Cl , Br~, I-, and H and the
organic groups such as, for example, acetoxy, formyloxy,
benzoyloxy, etc.
~ -17- 133819~
M can be any element from the Periodic Groups
IVB, VB, vIs~ VIIB, and vIIIs~ such as, for example, Ti,
zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co,
Rh, Ir, Ni, Pd and Pt.
Suitable anions, X, in formulas I and II, of use
as the counterion in the ionic salts of the organometallic
complex cation in the preferred radiation-sensitive
compositions of the invention are those in which X has the
formula DZr, wherein D is a metal from Groups IB to VIIIB
or a metal or metalloid from Groups IIIA to VA of the
Periodic Chart of Elements, Z is a halogen atom or a
hydroxy group, and r is an integer having a value of 1 to
6. Preferably, the metals are copper, zinc, titanium,
vanadium, chromium, manganese, iron, cobalt, or nickel and
the metalloids preferably are boron, aluminum, antimony,
tin, arsenic, and phosphorus. Preferably, the halogen, Z,
of formula II, is chlorine or fluorine. Illustrative of
suitable anions are BFq , PF6 , AsF6 , SbF6 , FeCl9 ,
SnCl5 , SbFs , AlF6 , GaCl4 , InFg , TiF6 , ZrF6 , etc-
Preferably, the anions are BFq , PF6 , SbF6 , SbF50H ,
AsF6 , and SbCl6 .
Additional suitable anions, X, in formulae I andII, of use as the counterion in the ionic salts of the
organometallic complex cations include those in which X is
an organic sulfonate. Illustrative of suitable
sulfonate-containing anions are CH3S03-, CF3S03-,
C6H5S03-, p-toluenesulfonate, p-chlorobenzenesulfonate and
related isomers and the like.
There are restrictions on the sum of electrons
donated by the ligands, Ll, L2, L3, and L4, of formula I
and L5 and L6 of formula II, and the valence electrons
possessed by the metal. For most complex compounds not
involving intramolecular metal-metal bonding, this sum is
governed by the "eighteen electron rule" [see J. Chem. Ed.,
46, 811 (1969)]. This rule is sometimes called the "nine
orbital rule", "the effective number rule", or the "rare
gas rule". This rule states that the most stable
organometallic compounds tend to be those compounds in
` ~ -18- 1338194
which the sum of the electrons donated by the ligands and
the metal is eighteen. Those skilled in the art, however,
know that there are exceptions to this rule and that
organometallic complex compounds having a sum of 16, 17,
19, and 20 electrons are also known. Some of these
complexes are transient. Therefore, ionic salts of
organometallic complex cations not including intramolecular
metal-metal bonding, described by formulas I and II in
which the complexed metal has a sum of 16, 17, 18, 19, or
20 electrons in the valence shell and a residual net
positive charge of 1 or 2, are included within the scope of
the invention.
For complex compounds described in formula I in
which intramolecular metal-metal bonding exists serious
departure from the "eighteen electron rule" can occur. It
has been proposed [J. Amer. Chem. Soc. 100, 5305 (1978)]
that the departure from the "eighteen electron rule" in
these transition metal complexes is due to the metal-metal
interactions destabilizing the metal p orbitals to an
extent to cause them to be unavailable for ligand bonding.
Hence, rather than count electrons around each metal
separately in a metal cluster, cluster valence electrons
(CVE) are counted. A binuclear complex, MM, is seen to
have 34 CVEs. Therefore, ionic salts of binuclear
organometallic complex cations are described by formula I
in which the complexed metal cluster, MM, has a sum of 34
CVEs in the valence shell and a residual net positive
charge of 1 or 2 are included within the scope of this
invention.
Suitable two-component curing agents which
include organometallic complex ionic salts described by
formulae I or II and onium salts described by formula III
of use in the compositions of the invention are those
combinations of salts that upon application of sufficient
energy, thermal, accelerated particle (electron beam), or
electromagnetic radiation having a wavelength from about
200 to 800 nm, will generate an active species capable of
catalyzing the polymerization of the compositions of the
` -19- 133819~
invention. The level of catalytic activity will, of
course, depend on the choice of metal, ligands, and
counterions in the organometallic salt and the particular
onium salt.
Examples of suitable salts of organometallic
complex cations useful in the composition of the invention
include the following (proposed structures of typical
compounds are shown at the end of the list):
(eta5-cyclopentadienyl)tricarbonyliron(l+)
hexafluorophosphate~)
(eta5-cyclopentadienyl)dicarbonylthiocarbonyliron(l+)
tetrafluoroborate
(eta5-cyclopentadienyl)carbonylbis-
(triphenylstibine)iron(l+) hexafluorophosphate
(eta5-cyclopentadienyl)tricarbonylruthenium(l+)
tetrachloroferrate
(eta5-cyclopentadienyl)dicarbonyltriphenylstibineiron(l+)
hexafluoroantimonate
(eta5-methylcyclopentadienyl)dicarbonylnitrosyl-
manganese(l+) hexafluoroantimonate~b)
(eta5-methylcyclopentadienyl)(eta3-allyl)dicarbonyl-
manganese(l+) tetrafluoroborate~'
(eta5-cyclopentadienyl)tetracarbonylmolybdenum(l+)
hexafluorophosphate
(eta5-pentadienyl)tricarbonyliron(l+) tetrafluoroborate
(eta5-cyclohexadienyl)tricarbonyliron(l+)
hexafluoroarsenate( d )
-20- 13~819~
(eta5-cyclohexadienyl)(ethylidene)carbonyltriphenyl-
phosphineiron(l+) tetrafluoroborate
(eta5-cyclopentadienyl)(ethoxymethylcarbene)carbonyl-
S triphenylphosphineiron(l+) tetrafluoroborate
(eta5-cyclopentadienyl)(dithiomethoxycarbene)-
dicarbonyliron(l+) hexafluorophosphate
(eta5-cyclopentadienyl)dicarbonylmethylisonitrileiron(l+)
hexafluoroarsenate
(eta6-toluene)tricarbonylmanganese(l+)
hexafluoroantimonate('
(eta6-mesitylene)tricarbonylrhenium(l+)
hexafluoroantimonate
(eta7-cycloheptatrienyl)tricarbonylchromium(l+)
hexafluorophosphate
(eta7-cycloheptatrienyl)tricarbonyltungsten(l+)
hexafluoroarsenate(f )
(eta5-cyclopentadienyl)(eta2-l-pentene)dicarbonyliron(l+)
tetrafluoroborate
(eta6-benzene)(eta5-cyclopentadienyl)iron(l+)
hexafluorophosphate
(eta6-mesitylene)(eta5-cyclopentadienyl)iron(l+)
tetrafluoroborate
(eta6-naphthalene)(eta5-cyclopentadienyl)iron(l+)
hexafluoroantimonate
(eta6-acetophenone)(eta5-methylcyclopentadienyl)iron(l+)
hexafluoroarsenate
-21- 133819~
bis(eta5-cyclopentadienyl)cobalt(l+) hexafluorophosphate
bis(eta5-cyclopentadienyl)iron(l+) hexafluoroantimonate
S bis(eta5-chlorocyclopentadienyl)nickel(l+)
hexafluorophosphate
bis(eta6-benzene)chromium(l+) hexafluoroantimonate~g)
bis(eta6-hexamethylbenzene)cobalt(2+) hexafluoroarsenate
bis(eta6-hexamethylbenzene)nickel(2+) hexafluoroantimonate
tetracarbonyltriphenylphosphinecobalt(l+)
lS hexafluorophosphate
tricarbonylbis(triphenylphosphine)iridium(l~)
hexafluorophosphate
(eta3-allyl)pentacarbonylchromium(l+) tetrafluoroborate
pentacarbonylnitrosylmolybdenum(l+) hexafluorophosphate
(eta3-allyl)tetracarbonyliron(l+) hexafluoroantimonate
hexacarbonylrhenium(l+) hexafluoroantimonate
bis(eta6-mesitylene)iron(2+) hexafluoroantimonate~ h )
bis(eta6-hexamethylbenzene)manganese(l+) tetrafluoroborate
bis(eta6-mesitylene)vanadium(l+) hexafluorophosphate
(eta7-cycloheptatrienyl)(eta5-cyclopentadienyl)manganese-
(l+) hexafluoroarsenate
(eta8-cyclooctatetraenyl)(eta5-cyclopentadienyl)chromium-
(l+) hexafluorophosphate
-22- 133819~
(eta6-fluorene)(eta5-cyclopentadienyl)iron(l+)
hexafluorophosphate(i)
(eta6-l-phenylborabenzene)(eta5-cyclopentadienyl)cobalt(l+)
hexafluorophosphate
(eta5-cyclopentadienyl)(eta5-N-methylpyrrolyl)iron(l+)
hexafluorophosphate
(eta6-2,3,4,5-tetrathiomethoxybenzene)(eta5-
cyclopentadienyl)iron(l+) hexafluoroarsenate
[(eta6-1,2,3,4,5,6)(eta6-7,8,9,10,11,12)biphenyl]-
bis(eta5-cyclopentadienyl)diiron(2+) tetrafluoroborate
[ (eta6-1,2,3,4,4a,9a) (eta6-5,6,7,8,8a,5a)fluorene]-
bis(eta5-cyclopentadienyl)diiron(2+) hexafluorophosphate
[ (eta6-1,2,3,4,4a,12a)(eta6-7,8,9,10,10a,6a)chrysene]-
bis(eta6-benzene)dichromium(2+) hexafluoroantimonate
dicarbonyl[bis(diphenylphosphino)ethane]bis(eta5-
cyclopentadienyl)diiron(l+) hexafluorophosphate
[(eta6-4,5,5a,28c,28b,3a)(eta6-8a,8b,20d,22a,22b,24c)-
lH,14H-dipyrano(3,4,5-gh: 3',4',5'-g'h')anthra(2",1",9":
4,5,6;6",5",10":4',5',6')diisoquino(2,1-a:2',1'-al)-
diperimidine]bis(eta5-cyclopentadienyl)diiron(2+)
hexafluoroantimonate
[(eta6-1,2,3,3a,13b,13a)benzo(10,11)chryseno(2,3-d)(1,3)-
dioxole](eta5-methylcyclopentadienyl)iron(l+)
hexafluorophosphate
[(eta6-1,2,3,3a,16c,16b)-
(eta6-9,10,11,lla,13c,8b)cycloocta(1,2,3,4-def:5,6,7,8-
d'e'f')diphenanthrene]bis-
(eta5-acetylcyclopentadienyl)diiron(2+) tetrafluoroborate
-23- 1338191
bis(eta5-acetylcyclopentadienyl)iron(l+) tetrafluoroborate
(eta3-l-methylallyl)tetracarbonyliron(+l)
hexafluorophosphate
(eta3-1,3-dimethylallyl)tetracarbonyliron(+l)
hexachloroantimonate
133819~
(a~ 24-
S OO O PF6- lO SbF6
(c) ~ (d) ~
/Mn~ BF4- /Fle\ AsF6
15O///c f ~ c ~cl c~
( e ) ~} ( f ) (~)
/ Mn ~ SbF6/ 1 \ ASF6
0// ~ C~\o //~ ~ ~
~}
Cr SbF6 Fe 2 SbF6
( i ) ~ =
Fe ~ PF6
-25-
1~ 3 8 1 9 4 60557-3623
Organometallic salts are known in the art and can be
prepared as disclosed in, for example, Canadian Application
Serial No. 440,864, Canadian Patent No. 1,300,307, U. S. Patent
Nos. 4,868,288 and 5,073,476. In addition to the compounds of
formulae I and II, all of the organometallic salts disclosed in
these references are useful in the present invention.
The bicomponent curing agent can be present in an
effective amount which is generally in the range of 0.01 to 20,
preferably 0.1 to 10 weight percent of the total composition. The
ratio of organometallic salt to onium salt is in the range of
10:1 to 1:10 by weight, preferably 5:1 to 1:5 by weight.
The present invention also provides a process for the
polymerization of one of ethylenically-unsaturated monomers
optionally in combination with polyurethane precursors or epoxy
monomers, or epoxy monomers only, or polyurethane precursors
only, comprising the steps of: (a) providing said at least one
ethylenically-unsaturated monomers optionally in combination with
polyurethane precursors or epoxy monomers, or at least one epoxy
compound, or polyurethane precursors, (b) adding to said
compound or compounds a combination of a catalytically effective
amount of a curing agent comprising an organometallic salt and
an onium salt (and all permutations of the order of mixing the
aforementioned components), thereby forming a polymerizable
mixture, and (c) allowing the mixture to polymerize or adding
energy to the mixture to affect polymerization.
In a further aspect, there is also provided a method
for preparing coated articles containing the cured composition
of the invention comprising the steps of: (a) providing a
-25a-
60557-3623
13381~)4
substrate, (b) coating an energy polymerizable mixture as
described above onto at least one surface of said substrate by
methods known in the art, such as bar, knife, reverse roll,
knurled roll, curtain, or spin coatings, or b~ dipping, spraying,
brushing, and the like, with or without a coating solvent, and
. . ~ .,
_ -26- 13381~4
(c) applying energy (after evaportion of
solvent if present and if desired) to the article to
cause the polymerization of the coating.
In a still further aspect, there are also
provided shaped articles comprising the polymerizable
mixture of the invention. The articles can be provided,
for example, by techniques such as molding, injection
molding, casting, and extrusion. Applying energy to the
mixture causes polymerization and provides the cured shaped
article.
It may be desirable to add solvent to solubilize
components and aid in processing. Solvent, preferably
organic solvent, in an amount up to 99 weight percent, but
preferably in the range of 0 to 90 weight percent, most
preferably in the range of 0 to 75 weight percent, of the
polymerizable composition can be used.
A wide variety of monomers can be energy
polymerized using the curing agent of the invention.
Suitable compounds containing at least one ethylenically-
unsaturated double bond, can be monomers and/or oligomers
such as (meth)acrylates, (meth)acrylamides, and vinylcompounds, and are capable of undergoing free radical
polymerization. Such monomers include mono-, di-, or poly-
acrylates and methacrylates such as methyl acrylate, methyl
methacrylate, ethyl acrylate, isopropyl methacrylate,
isooctyl acrylate, acrylic acid, n-hexyl acrylate, stearyl
acrylate, allyl acrylate, glycerol diacrylate, glycerol
triacrylate, ethyleneglycol diacrylate, diethyleneglycol
diacrylate, triethyleneglycol dimethacrylate,
1,3-propanediol diacrylate, 1,3-propanediol dimethacrylate,
trimethylolpropane triacrylate, 1,2,4-butanetriol
trimethylacrylate, 1,4-cyclohexanediol diacrylate,
pentaerythritol triacrylate, pentaerythritol
[tetraacrylate, pentaerythritol tetramethacrylate, sorbitol
hexacrylate, bis[1-(2-acryloxy)]-p-ethoxyphenyl-
dimethylmethane, bis[1-(3-acryloxy-2-hydroxy)]-p-
propoxyphenyl-dimethylmethane, tris-hydroxyethyl-
isocyanurate trimethacrylate; the bis-acrylates and
-27- 133819~
bis-methacrylates of polyethylene glycols of molecular
weight 200-500, copolymerizable mixtures of acrylated
monomers such as those of U.S. Patent No. 4,652,274, and
acrylated oligomers such as those of U.S. Patent No.
4,642,126; bireactive monomers such as
epoxy (meth)acrylates, isocyanato (meth)acrylates, and
hydroxy (meth)acrylates, preferred examples including
hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate,
isocyanatoethyl (meth)acrylate, glycidyl (meth)acrylate,
and m-isopropenyl-alpha,alpha-dimethylbenzyl isocyanate;
unsaturated amides such as acrylamide, methylene
bis-acrylamide, methylene bis-methacrylamide,
1,6-hexamethylene bis-acrylamide, diethylene triamine
tris-acrylamide and beta-methacrylaminoethyl methacrylate;
and vinyl compounds such as styrene, divinylbenzene diallyl
phthalate, divinyl succinate, divinyl adipate, divinyl
phthalate, and vinyl azlactones as disclosed in U.S. Patent
No. 4,304,705. Mixtures of two or more monomers can be
used if desired. Bireactive monomers are particularly
useful to achieve crosslinking of two different
polymerizable species.
The polyisocyanate component of the polyurethane
precursors that can be cured or polymerized in the
bicomponent curing systems of the present invention may be
any aliphatic, cycloaliphatic, araliphatic, aromatic, or
heterocyclic polyisocyanate, or any combination of such
polyisocyanates. Particularly suitable polyisocyanates
correspond to the formula
Q(NCO)p IV
in which p is an integer 2 to 4, and Q represents an
aliphatic hydrocarbon di-, tri-, or tetra-radical
containing from 2 to 100 carbon atoms, and zero to 50
heteroatoms, a cycloaliphatic hydrocarbon radical
containing from 4 to 100 carbon atoms and zero to 50
heteroatoms, an aromatic hydrocarbon radical or
heterocyclic aromatic radical containing from 5 to 15
~ -28- 1~8194
carbon atoms and zero to 10 heteroatoms, or an araliphatic
hydrocarbon radical containing from 8 to 100 carbon atoms
and zero to 50 heteroatoms. The heteroatoms that can be
present in Q include non-peroxidic oxygen, sulfur, non-
amino nitrogen, halogen, silicon, and non-phosphino
phosphorus.
Examples of polyisocyanates are as follows:
ethylene diisocyanate, 1,4-tetramethylene diisocyanate,
1,6-hexamethylene diisocyanate, trimethyl hexamethylene
diisocyanate, 1,12-dodecane diisocyanate,
cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and
-1,4-diisocyanate and mixtures of these isomers,
l-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane
(see German Auslegenschrift No. 1,202,785, U.S. Patent No.
3,401,190), 2,4- and 2,6-hexahydrotolylene diisocyanate and
mixtures of these isomers, hexahydro-1,3- and/or -1,4-
phenylene diisocyanate, perhydro-2,4'- and/or -4,4'-
diphenylmethane diisocyanate, 1,3- and 1,4-phenylene
diisocyanate, 2,4- and 2,6-tolylene diisocyanate and
mixtures of these isomers, diphenylmethane-2,4'- and/or -
4,4'-diisocyanate, naphthylene-1,5-diisocyanate, and the
reaction products of four equivalents of the aforementioned
isocyanate-containing compounds with compounds containing
two isocyanate-reactive groups.
According to the present invention, it is also
possible, for example, to use triphenyl
methane-4,4',4"-triisocyanate, polyphenyl polymethylene
polyisocyanates described in British Patent Nos. 874,430
and 848,671, m- and p-isocyanatophenyl sulphonyl
isocyanates according to U.S. Patent No. 3,454,606,
perchlorinated aryl polyisocyanates of the type described,
for example, in German Auslegeschrift No. 1,157,601 ~U.S.
Pat. No. 3,277,138), polyisocyanates containing
carbodiimide groups of the type described in U.S. Patent
No. 3,152,162 and in German Offenlegungsschrift Nos.
2,504,400, 2,537,685 and 2,552,350, norbornane
diisocyanates according to U.S. Patent No. 3,492,330,
polyisocyanates containing allophanate groups of the type
133~19~
~ - 29 -
descrlbed, for example, ln Brltlsh Patent No. 994,890, ln
Belglan Pat No. 761,626 and ln U.S. Patent 3,769,318,
polylsocyanates contalnlng lsocyanurate groups of the type
descrlbed, for example ln U.S. Patent No. 3,001,973, ln German
Patent Nos. 1,022,789, 1,222,067 and 1,027,394 and German
Offenlegungsschrlft Nos. 1,929,034 and 2,004,048, poly-
lsocyanates contalnlng urethane groups of the type descrlbed,
for example, ln Belglan Patent No. 752,261 or ln U.S. Patent
Nos. 3,394,164 and 3,644,457, polylsocyanates contalnlng
acrylated urea groups accordlng to German Patent No.
1,230,778, polylsocyanates contalnlng bluret groups of the
type descrlbed, for example, ln U.S. Patent Nos. 3,124,605,
3,201,372 and 3,124,605 and ln Brltlsh Patent No. 889,050,
polylsocyanates produced by telomerlzatlon reactlons of the
type descrlbed for example ln U.S. Patent No. 3,654,106,
polylsocyanates contalnlng ester groups of the type descrlbed,
for example, ln Brltlsh Patent Nos. 965,474 and 1,072,956, ln
U.S. Patent No. 3,567,763 and ln German Patent No. 1,231,688,
reactlon products of the above-mentloned dllsocyanates wlth
acetals accordlng to German Patent 1,072,385 and polylso-
cyanates contalnlng polymerlc fatty acld esters accordlng to
U.S. Patent No. 3,455,883.
It ls also posslble to use dlstlllatlon resldues
havlng lsocyanate groups obtalned ln the commerclal productlon
of lsocyanates, optlonally ln solutlon ln one or more of the
above-mentloned polylsocyanates. It ls also posslble to use
any mlxtures of the above-mentloned polylsocyanates.
Preferred polylsocyanates are hexamethylene
dllsocyanate, lts lsocyanurate and lts bluret;
4,4'-methylenebls(cyclohexyllsocyanate); 1-lsocyanato-3,3,5-
trlmethyl-5-lsocyanatomethyl cyclohexane (lsophorone dllso-
cyanate); the tolylene dllsocyanates and thelr lsocyanurates;
the mlxed lsocyanurate of tolylene dllsocyanate and hexa-
methylene dllsocyanate; the reactlon product of 1 mol of
trlmethylol propane and 3 mols of tolylene dllsocyanate and
also crude dlphenyl methane dllsocyanate.
60557-3623
_ -30-
1338194
Also useful are blocked polyisocyanates, which
are known in the art and are commercially available,
wherein the blocking group can be, for example, phenol,
epsilon-caprolactam, hydroxamic acid ester, ketoxime,
t-butyl acetoacetate, and others described in z.w. Wicks,
Jr., "Progress in Organic Coatings", 9 pp. 3-28 (1981).
Suitable compounds containing at least 2
isocyanate-reactive hydrogen atoms can be high or low
molecular weight compounds, having a weight average
molecular weight, generally from about 50 to 50,000. In
addition to compounds containing amino groups, thiol groups
or carboxyl groups, are, preferably, compounds containing
hydroxyl groups, particularly compounds containing from
about 2 to 50 hydroxyl groups and above all, compounds
having a weight average molecular weight of from about 500
to 25000, preferably from about 700 to 2000, for example,
polyesters, polyethers, polythioethers, polyacetals,
polycarbonates, poly(meth)acrylates, and polyester amides,
containing at least 2, generally from about 2 to 8, but
preferably from about 2 to 4 hydroxyl groups, or even
hydroxyl-containing prepolymers of these compounds and a
less than equivalent quantity of polyisocyanate, of the
type known for the production of polyurethanes.
Representatives of the above-mentioned compounds
used in accordance with the present invention are
described, for example, in High Polymers, Vol. XVI,
"Polyurethanes, Chemistry and Technology", By Saunders and
Frisch, Interscience Publishers, New York/London, and Vol.
I, 1962, pages 32 to 42 and pages 44 to 54 and Vol. II,
1964, pages 5-6 and 198-199, and in "Kunststoff-Handbuch",
Vol. VII, Vieweg-Hochtlen, Carl-HanserVerlag, Munich, 1966,
for example, on pages 45 to 71. It is, of course, possible
to use mixtures of the above-mentioned compounds containing
at least two isocyanate-reactive hydrogen atoms and having
a molecular weight of from about 50 to 50,000 for example,
mixtures of polyethers and polyesters.
In some cases, it is particularly advantageous
to combine low-melting and high-melting polyhydroxyl
containing compounds with one another (German
Offenlegungsschrift No. 2,706,297).
~ -31- 1338191
Low molecular weight compounds containing at
least two isocyanate-reactive hydrogen atoms (molecular
weight from about 50 to 400) suitable for use in accordance
with the present invention are compounds preferably
containing hydroxyl groups and generally containing from
about 2 to 8, preferably from about 2 to 4 isocyanate-
reactive hydrogen atoms. It is also possible to use
mixtures of different compounds containing at least two
isocyanate-reactive hydrogen atoms and having a molecular
weight in the range of from about 50 to 400. Examples of
such compounds are ethylene glycol, 1,2- and 1,3-propylene
glycol, 1,4- and 2,3-butylene glycol, 1,5-pentane diol,
1,6-hexane diol, 1,8-octane diol, neopentyl glycol,
1,4-bis-hydroxymethyl cyclohexane, 2-methyl-1,3-propane
diol, dibromobutene diol (U.S. Patent No. 3,723,392),
glycerol, trimethylolpropane, 1,2,6-hexanetriol,
trimethylolethane, pentaerythritol, quinitol, mannitol,
sorbitol, diethylene glycol, triethylene glycol,
tetraethylene glycol, higher polyethylene glycols,
dipropylene glycol, higher polypropylene glycols,
dibutylene glycol, higher polybutylene glycols,
4,4'-dihydroxy diphenyl propane and dihydroxy methyl
hydroquinone.
Other polyols suitable for the purposes of the
present invention are the mixtures of hydroxy aldehydes and
hydroxy ketones ("formose") or the polyhydric alcohols
obtained therefrom by reduction ("formitol") which are
formed in the autocondensation of formaldehyde hydrate in
the presence of metal compounds as catalysts and compounds
capable of enediol formation as co-catalysts (German
Offenlegungsschrift Nos. 2,639,084, 2,714,084, 2,714,104,
2,721,186, 2,738,154 and 2,738,512). Solutions of
polyisocyanate polyaddition products, particularly
solutions of polyurethane ureas containing ionic groups
and/or solutions of polyhydrazodicarbonamides, in low
molecular weight polyhydric alcohols may also be used as
the polyol component in accordance with the present
invention (German Offenlegungsschrift No. 2,638,759).
_ -32- 1338194
Many other compounds containing isocyanate-
reactive hydrogen atoms and polyisocyanates are useful in
the present invention, and are obvious to those skilled in
the art of polyurethane science and technology.
Epoxy compounds that can be cured or polymerized
by the bicomponent curing agents of this invention, using
the latter in a catalytically effective amount, are those
known to undergo cationic polymerization and include 1,2-,
1,3-, and 1,4-cyclic ethers (also designated as 1,2-, 1,3-,
and 1,4-epoxides). The 1,2-cyclic ethers are preferred.
The cyclic ethers which can be polymerized in
accordance with this invention include those described in
"Ring-Opening Polymerizations", Vol. 2, by Frisch and
Reegan, Marcel Dekker, Inc. (1969). Suitable 1,2-cyclic
ethers are the monomeric and polymeric types of epoxides.
They can be aliphatic, cycloaliphatic, aromatic, or
heterocyclic and will typically have an epoxy equivalency
of from 1 to 6, preferably 1 to 3. Particularly useful are
the aliphatic, cycloaliphatic, and glycidyl ether type
1,2-epoxides such as propylene oxide, epichlorohydrin,
styrene oxide, vinylcyclohexene oxide, cyclohexeneoxide,
vinylcyclohexene dioxide, glycidol, butadiene oxide,
glycidyl methacrylate, diglycidyl ether of bisphenol A,
3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate,
3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-
methylcyclohexanecarboxylate,
bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate,
dicyclopentadiene dioxide, epoxidized polybutadiene,
1,4-butanediol diglycidyl ether, polyglycidyl ether of
phenolformaldehyde resole or novolak resin, resorcinol
diglycidyl ether, and epoxy silicones, e.g.,
dimethylsiloxanes having cycloaliphatic epoxide or glycidyl
ether groups.
A wide variety of commercial epoxy resins are
available and listed in "Handbook of Epoxy Resins" by Lee
and Neville, McGraw Hill Book Company, New York (1967) and
in "Epoxy Resin Technology" by P. F. Bruins, John Wiley &
Sons, New York (1968). Representative of the 1,3- and
1~8194
- 33 -
1,4-cycllc ethers whlch can be polymerlzed ln accordance wlth
thls lnventlon are oxetane, 3,3-blstchloromethyl)oxetane, and
tetrahydrofuran.
In partlcular, cycllc ethers whlch are readlly
avallable lnclude propylene oxlde, oxetane, eplchlorohydrln,
tetrahydrofuran, styrene oxlde, cyclohexeneoxlde, vlnylcyclo-
hexene oxlde, glycldol, glycldyl methacrylate, octylene oxlde,
phenyl glycldyl ether, 1,2-butane oxlde, dlglycldyl ether of
blsphenol A (e.g., "Epon 828" and ~DER 331"), vlnylcyclohexene
dloxlde (e.g., ~ERL 4206"), 3,4-epoxycyclohexylmethyl-3,4-
epoxycyclohexanecarboxylate (e.g., "ERL -4221"), 3,4-epoxy-6-
methylcyclohexanecarboxylate (e.g., "ERL -4201"), bls(3,4-
epoxy-6-methylcyclohexylmethyl)adlpate (e.g., "ERL -4289"),
allphatlc epoxy modlfled wlth polypropylene glycol (e.g., "ERL
4050" and "ERL -4052"), dlpentene dloxlde (e.g., "ERL 4269"),
epoxldlzed polybutadlene (e.g., "Oxlron 2001"), slllcone epoxy
(e.g., "Syl-Kem 90"), 1,4-butanedlol dlglycldyl ether (e.g.,
Araldlte RD-2), polyglycldyl ether of phenolformaldehyde
novolak (e.g., "DER -431", "Epl-Rez 521" and "DER -438"),
resorclnol dlglycldyl ether (e.g., ~Kopoxlte "), polyglycol
dlepoxlde (e.g., "DER 736"), polyacrylate epoxlde (e.g.,
"Epocryl U-14"), urethane modlfled epoxlde (e.g., "QX3599 "),
polyfunctlonal flexlble epoxldes (e.g., "Flexlblllzer 151"),
and mlxtures thereof as well as mlxtures thereof wlth co-
curatlves, curlng agents, or hardeners whlch also are well
known (see Lee and Nevllle and Brulns, supra). Representatlve
of the co-curatlves of hardeners whlch can be used are acld
anhydrldes such as nadlc methyl anhydrlde, cyclopentanetetra-
carboxyllc dlanhydrlde, pyromellltlc anhydrlde, cls-1,2-
cyclohexanedlcarboxyllc anhydrlde, and mlxtures thereof.
Where ethylenlcally-unsaturated compounds are used
ln comblnatlon wlth an epoxy monomer or a polyurethane pre-
cursor, the polymerlzable components can be present ln any
proportlon, preferably 0.1~99.9 to 99.9:0.1, more preferably
1:99 to 99:1, most preferably 2:98 to 98:2 parts by welght.
Trade mark
60557-3623
-_ ~34~ 133819~
In general, radiation-induced polymerization of
ethylenically-unsaturated monomers, optionally in
combination with polyurethane precursors or epoxy monomers,
or epoxy monomers, or polyurethane precursors with latent
curing agents comprising an organometallic salt and an
onium salt can be carried out at room temperature for the
majority of energy curable compositions, although low
temperature (e.g., -10C) or elevated temperature (e.g., 30
to 400C, preferably 50 to 300C) can be used to subdue the
exotherm of polymerization or to accelerate the
polymerization, respectively. Temperature of
polymerization and amount of catalyst will vary and be
dependent on the particular curable composition used and
the desired application of the polymerized or cured
product. The amount of curing agent to be used in this
invention should be sufficient to effect polymerization of
the monomers or precursors (i.e., a catalytically-effective
amount) under the desired use conditions. Such amount
generally will be in the range of about 0.01 to 20 weight
percent, and preferably 0.1 to 10.0 weight percent, based
on the weight of curable composition.
Solvents, preferably organic, can be used to
assist in dissolution of the curing agent in the
ethylenically-unsaturated monomer, the polyurethane
precursors, or the epoxy monomers, and as a processing aid.
Representative solvents include acetone, methyl ethyl
ketone, cyclopentanone, methyl cellosolve acetate,
methylene chloride, nitromethane, methyl formate,
acetonitrile, gamma-butyrolactone, and 1,2-dimethoxyethane
(glyme). In some applications, it may be advantageous to
adsorb the curing agents onto an inert support such as
silica, alumina, clays, etc., as described in U.S. Patent
No. 4,677,137.
For those compositions of the invention which
are radiation-sensitive, i.e., any source of radiation
including accelerated particles (e.g. electron beam
radiation) and radiation sources emitting active radiation
in the ultraviolet and visible region of the spectrum
~35~ 1338 19~
(e.g., about 200 to 800 nm) can be used. Suitable sources
of radiation include mercury vapor discharge lamps, carbon
arcs, tungsten lamps, xenon lamps, lasers, sunlight, etc.
The required amount of exposure to effect polymerization is
dependent upon such factors as the identity and
concentrations of the organometallic salt and onium salt,
the particular ethylenically unsaturated monomer,
polyurethane precursors, or epoxy monomers, the thickness
of the exposed material, type of substrate, intensity of
the radiation source and amount of heat associated with the
radiation.
Optionally, it is within the scope of this
invention to include photosensitizers or photoaccelerators
in the radiation-sensitive compositions. Use of
photosensitizers or photoaccelerators alters the wavelength
sensitivity of radiation-sensitive compositions employing
the latent catalysts of this invention. This is
particularly advantageous when the latent catalyst does not
strongly absorb the incident radiation. Use of a
photosensitizer or photoaccelerator increases the radiation
sensitivity, allowing shorter exposure times and/or use of
less powerful sources of radiation. Any photosensitizer or
photoaccelerator may be useful if its triplet energy is at
least 45 kilocalories per mole. Examples of such
photosensitizers are given in Table 2-1 of the reference,
Steven L. Murov, Handbook of Photochemistry, Marcel Dekker
Inc., NY, 27-35 (1973), and include pyrene, fluoranthrene,
xanthone, thioxanthone, benzophenone, acetophenone, benzil,
benzoin and ethers of benzoin, chrysene, p-terphenyl,
acenaphthene, naphthalene, phenanthrene, biphenyl,
substituted derivatives of the preceding compounds, and the
like. When present, the amount of photosensitizer or
photoaccelerator used in the practice of the present
invention is generally in the range of 0.01 to 10 parts,
and preferably 0.1 to 1.0 parts, by weight of
photosensitizer or photoaccelerator per part of
organometallic salt.
_ -36- 133819~
Thermal polymerization using direct heating or
infrared electromagnetic radiation, as is known in the art,
can be used to cure the compositions according to the
teachings of this invention.
It is within the scope of this invention to
include two-stage polymerization (curing), by first
activating the curing agent by irradiating the curable
compositions and subsequently thermally curing the
activated precursors so obtained, the irradiation
temperature being below the temperature employed for the
subsequent heat-curing. The activated precursors may
normally be cured at temperatures which are substantially
lower than those required for the direct thermal curing,
with an advantage in some cases in the range from 50 to
110C. This two-stage curing also makes it possible to
control the polymerization in a particularly simple and
advantageous manner.
Adjuvants such as solvents, pigments, abrasive
granules, stabilizers, light stabilizers, antioxidants,
flow agents, bodying agents, flatting agents, colorants,
inert fillers, binders, blowing agents, fungicides,
bacteriocides, surfactants, plasticizers, and other
additives as known to those skilled in the art can be added
to the compositions of this invention. These can be added
in an amount effective for their intended purpose.
Compositions of this invention are useful for
coatings, foams, shaped articles, adhesives, filled or
reinforced composites, abrasives, caulking and sealing
compounds, casting and molding compounds, potting and
encapsulated compounds, impregnating and coating compounds,
and other applications which are known to those skilled in
the art.
Compositions of this invention may be applied,
preferably as a liquid, to a substrate such as steel,
aluminum, copper, cadmium, zinc, ceramic, glass, paper,
wood, or various plastic films such as poly(ethylene
terephthalate), plasticized poly(vinylchloride),
poly(propylene), poly(ethylene), and the like, and
~ -37- 133819~
irradiated. By polymerizing part of the coating, as by
irradiation through a mask, those sections which have not
been exposed may be washed with a solvent to remove the
unpolymerized portions while leaving the photopolymerized,
insoluble portions in place. Thus, compositions of this
invention may be used in the production of articles useful
in the graphic arts such as printing plates and printed
circuits. Methods of producing printing plates and printed
circuits from photopolymerizing compositions are well known
in the art (see for example British Patent Specification
No. 1,495,746).
Objects and advantages of this invention are
further illustrated by the following examples, but the
particular materials and amounts thereof recited in these
examples, as well as other conditions and details, should
not be construed to unduly limit this invention. In the
examples, all parts are parts by weight unless indicated
otherwise. All examples were prepared in ambient
atmosphere (in the presence of oxygen and water vapor)
unless indicated otherwise.
EXAMPLE 1
This example demonstrates the simultaneous
curing of ethylenically unsaturated and epoxy monomers in a
crosslinkable system. The curable composition consisted of
methyl acrylate, cyclohexene oxide and glycidyl acrylate.
If only epoxy or acrylate cure were initiated, then this
system produced a soluble polymer. If both epoxy and
acrylate cure were initiated then a crosslinked insoluble
polymer was produced.
Sample preparations were carried out under
subdued lights (below the level necessary to initiate
polymerization). The polymerizable mixture consisted of
1.0 g glycidyl acrylate, 5.0 g methyl acrylate and 5.0 g
cyclohexene oxide. In all cases there was added to the
polymerizable compositions 0.1 g of the desired
organometallic salt and 0.1 g diphenyliodonium
hexafluorophosphate. A 3 g portion of the composition was
_ -38- 1338191
placed in a glass vial and irradiated between two 15 watt
G.E. daylight fluorescent bulbs using an Ultraviolet
Products lamp holder (lamp separation distance 4 cm). The
sample was purged with nitrogen for one minute preceding
and continuously during photolysis. The irradiation time
required to produce a polymer insoluble in chloroform was
recorded, and is noted in Table I.
Alternatively, these compositions can be cured
thermally or in a two-stage process.
_ ~39~ 133 8194
TABLE I
Simultaneous Photoinitiation of Free Radical
and Epoxy Cure in a Crosslinkable System
Cure
5 Compound Time'
(eta6-mesitylene-)(eta5-cyclopentadienyl)- 75
iron(l+) hexafluorophosphate
(eta6-mesitylene)(eta5-cyclopentadienyl)- 70
iron(1+) hexafluoroantimonate
10 (eta6-naphthalene)(eta5-cyclopentadienyl)- 75
iron(1+) hexafluorophosphateb
(eta6-naphthalene)(eta5-cyclopentadienyl)- 60
iron(1+) hexafluoroantimonate
(eta6-1,2,3,4,4a,9a-(9-cinnamylidenefluorene))- 300
(eta5-cyclopentadienyl)iron(l+)
hexafluorophosphate
(eta5-cyclopentadienyl)dicarbonyl- 220
triphenylphosphineiron(1+)
hexafluorophosphate
(eta5-cyclopentadienyl)dicarbonyl- 300
triphenylphosphineiron(1+)
hexafluoroarsenate
(eta5-cyclopentadienyl)dicarbonyl- 200
triphenylphosphineiron(1+)
hexafluoroantimonate
(eta5-cyclopentadienyl)dicarbonyl- 120
triphenylarsineiron(1+)
hexafluoroarsenate
(eta5-cyclopentadienyl)dicarbonyl- 135
triphenylarsineiron(1+)
hexafluoroantimonate
(eta5-cyclopentadienyl)dicarbonyl- 130
triphenylstibineiron(l+)
hexafluoroantimonate
~ _40_ 1338194
Time in seconds to produce insoluble crosslinked system.
Diphenyliodonium hexafluorophosphate (comparative) alone
under these conditions did not produce a crosslinked
system after 20 minutes of irradiation.
b 0.2 g of gamma-butyrolactone added to completely
solubilize this compound.
The data of TABLE I show that bicomponent
initiators are efficient curing agents for free radical
and epoxy polymerization.
EXAMPLE 2
Curing trials using cationic organometallic salts
and onium salts as photoinitiators for free radically cured
monomers were conducted in the following manner: exposures
were made on a hot plate covered with a large aluminum
plate to keep the temperature constant. The light source
was a 275 watt Sylvania sunlamp positioned 10 cm above the
sample. For free radical polymerization, a stock solution
was prepared from of 0.1 g cationic organometallic salt
and/or iodonium hexafluorophosphate salt, 0.2 g
gamma-butyrolactone, 10 g 1,6-hexanedioldiacrylate. The
testing sample consisted of 1 g of the stock solution and
1 g of pentaerythritol tetraacrylate (SR-295TM, Sartomer
Co., West Chester, PA). Approximately 0.2 g of this sample
was placed in individual aluminum containers to evaluate
for cure times. The results of these trials are presented
in Table II.
~ -41-
1338194
TABLE II
Acrylate Cure Times
Catalyst System Cure Timea
(eta6-mesitylene)(eta5-cyclopentadienyl)- c10 sec
iron(1+) hexafluoroantimonate/IODONIUM
IODONIUM (comparative) >300 sec
(eta5-cyclopentadienyl)dicarbonyl- <30 sec
triphenylphosphineiron(1+)
hexafluoroarsenate/IODONIUM
at 80C in the air
IODONIUM in all Examples is diphenyliodonium
hexafluorophosphate
Essentially no cure took place when these samples were
heated in the dark for 4 hours at 80C.
EXAMPLE 3
Curing trials using organometallic salts and
onium salts as photoinitiators for epoxy monomers were
conducted in the following manner: Exposures were made on
a hot plate covered with a large aluminum plate to keep the
temperature constant. The light source was a 275 watt
Sylvania sunlamp positioned 10 cm above the sample. For
epoxy cure, the composition consisted on 0.1 g of the
organometallic salt and/or 0.1 g of the iodonium salt, 0.2
g gamma-butyrolactone and 10 g of a 1/9, w/w, mixture of
polyethylene glycol, m.wt. 400 (CarbowaxTM 400, Union
Carbide, Danbury, CT) and 3,4-epoxycyclohexylmethyl-3,4-
epoxycyclohexanecarboxylate (ERLTM-4221, Union Carbide,
Danbury, CT). Approximately 0.2 g of this sample was
placed in individual aluminum containers to evaluate for
cure times. The results of these trials are shown in Table
III below.
_ -42- 133819~
TABLE III
Epoxy Cure Times
Catalyst SystemCure Time
(eta6-mesitylene)(eta5-cyclopentadienyl)- >7 mina
iron(l~) hexafluoroantimonate (comparative)
(eta6-mesitylene)(eta5-cyclopentadienyl)- 7 min~
iron(l+) hexafluoroantimonate/IODONIUM
IODONIUM (comparative) >10 min~
(eta5-cyclopentadienyl)dicarbonyl- >30 minb
triphenylphosphineiron(l+)
hexafluoroarsenate (comparative)
(eta5-cyclopentadienyl)dicarbonyl- 30 minb
triphenylphosphineiron(l+)
hexafluoroarsenate/IoDoNIuM
15 IODONIUM(comparative) >30 minb
A at 90C in the air
b at 80C in the air
Essentially no cure took place when these samples were
heated in the dark for 4 hours at 80C.
As can be seen from the results in Tables II and
III, the combination of cationic organometallic salt and
onium salt does provide a more efficient photoinitiation
system than comparative curing agents while possessing good
thermal stability in the dark.
EXAMPLE 4
More quantitative information on the relative
activity of the combination organometallic salt and onium
salt initiator was obtained from a series of nmr trials
carried out to measure the degree of conversion from
monomer to polymer. The results of these trials are
presented in Table IV below. The trial which produced the
results in Table IV was carried out in the following
manner: A 1/1, w/w, mixture of methyl acrylate/cyclohexene
oxide was prepared. To a 10g sample of this mixture was
-43- 133 819~
added 0.1g of the desired cationic organometallic salt
and/or 0.lg of diphenyliodonium hexafluorophosphate. In a
small vial was placed 2g of the sample and it was purged
with nitrogen for 1 min before and continually during
irradiation. The light source was two 15 watt Sylvania
daylight fluorescent bulbs. Irradiation time was 3
minutes. Immediately after completion of the photolysis,
the nmr was taken in CDCl3. The amount of polymerization
was determined by the ratio of the peak intensity of the
polymer to that of polymer plus monomer.
TABLE IV
Percent Conversion to Polymer from NMR Study~
Catalyst System Epoxy Acrylate
15(eta6-mesitylene)(eta5-cyclopentadienyl)- 97.5% 58.5%
iron(1+) hexafluoroantimonate (comparative)
(eta6-mesitylene)(eta5-cyclopentadienyl)- 53.5% 47.3%
iron(l+) hexafluoroantimonate/IODONIUM
(eta6-mesitylene)(eta5-cyclopentadienyl)- 47.7% 41.8%
20iron(1+) hexafluorophosphate (comparative)
(eta6-mesitylene)(eta5-cyclopentadienyl)- 47.6% 49.1%
iron(1+) hexafluorophosphate/IONODIUM
IODONIUM (comparative) <0.5% 5.3%
~ Nmrs taken on a 400 MHz instrument
The data in Table IV show that the combination of
cationic organometallic salt and onium salt is an efficient
photoinitiation system for free radical and epoxy
polymerization.
EXAMPLE 5
More quantitative information on the relative
activity of this combination of initiators was obtained
from a series of nmr trials carried out to measure the
degree of conversion from monomer to polymer. The results
of these trials are presented in Table V below. The trial
~44~ 1~ 38 19~
which produced the results in Table V was carried out in
the following manner: A 1/1, w/w, mixture of methyl
acrylate/cyclohexeneoxide was prepared. To a 5.0g sample
of this mixture was added 0.046g of the desired cationic
orgnaometallic salt and/or 0.030g of diphenyliodonium
hexafluorophosphate. In a small vial was placed lg of the
sample and it was purged with nitrogen for 1 min before and
continually during irradiation. The light source was two
15 watt G.E. blacklite bulbs. Irradiation time was 4
minutes. Immediately after completion of the photolysis,
the nmr was taken in DCDl3. The amount of polymerization
was determined by the ratio of the peak intensity of the
polymer to that of polymer plus monomer.
TABLE V
Percent Conversion to Polymer from NMR Study~
Catalyst System Epoxy Acrylate
(eta5-cyclopentadienyl)dicarbonyl- 26% 28%
triphenylphosphineiron(l+)
hexafluoroarsenate (comparative)
(eta5-cyclopentadienyl)dicarbonyl- 35% 36%
triphenylphosphineiront1+)
hexafluoroarsenate/IODONIUM
IODONIUM (comparative) 22% 27%
Nmrs taken on a 400 MHz instrument
The data in Table V show that the combination of
cationic organometallic salt and onium salt is an efficient
photoinitiation system for free radical and epoxy
polymerization.
EXAMPLE 6
This example demonstrates the simultaneous
photocuring of two-part polyurethanes and acrylates.
A stock solution was prepared containing 1.5
parts hexane diisocyanate (Aldrich Chemical Co., Milwaukee,
- - 1338191
Wlsconsln), 3.5g poly(ethylene glycol) (CarbowaxR 400, Unlon
Carblde, Danbury, Connectlcut, molecular welght 400), and 5
parts dlstllled methyl acrylate (Aldrlch). Four samples were
prepared from l.lg stock solutlon and lnltlator comblnatlon
shown ln TABLE VI below. Sample 1 was left ln the dark at
room temperature. Samples 2, 3, and 4 were placed ln a water
bath at 73 + 1C, and lrradlated wlth a Kodak Carousel'~
Pro~ector contalnlng a 360 nm cutoff fllter for 5.0 mlnutes.
The samples were left ln the water bath ln the dark for an
addltlonal 2.0 mlnutes, then analyzed for percent converslon
of monomer to polymer by 400 MHz lH nmr. The results are
llsted ln Table VI below.
TABLE VI
Dual Cure of Urethane and Acrylate
Composltlon : Percent Converslon from NMR StudY
Sample
No. PhotocatalYst (welqht %) Urethane Acrylate
1 None (0%) (comparatlve) 0% 0%
2 IODONIUM (1%) (comparatlve) 0% 2%
3 (etaS-mesltylene) (etaS- 94% 54%
cyclopentadlenyl)lron(l+)
hexafluorophosphate (1%)/
IODONIUM (1%)
4 (eta'-mesltylene) (etaS- 76% 32%
cylcopentadlenyl)lron(l+)
hexafluorophosphate (1%)
(comparatlve)
The data of TABLE VI show that two-component curlng
agents are efflclent lnltlators for the comblnatlon free
radlcal and polyurethane precursor composltlons.
60557-3623
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EXAMPLE 7
A stock solutlon was prepared from of 2 parts hexane
dllsocyanate, 3.5 parts poly(ethylene glycol) (molecular
welght 400), 5 parts methyl acrylate, and 0.3 parts
hydroxyethyl acrylate (Aldrlch Chemlcal Co.). To 3.0 g
allquots was added sufflclent photocatalyst to reach the
concentratlon shown in TABLE VII. Samples were placed ln an
open vlal ln a water bath malntalned at 70+2C and lrradlated
uslng a KodakT~ Carousel'~ pro~ector contalnlng a 360 nm cutoff
fllter at a dlstance of 16 cm. At 1 mlnute lntervals allquots
(1/4 ml) of the lrradlated sample were added to 1/2 ml
chloroform wlth stlrrlng. The gel tlme was the earllest tlme
at whlch the allquot falled to dlssolve ln the chloroform, and
ls recorded ln TABLE VII below.
TABLE VII
Gel tlmes for Dual Curlnq sYstems
CatalYst (wgt. %) Gel Tlme
(eta6-mesltylene) (eta5-cyclopentadlenyl) 7 mln
lron (l+) hexafluorophosphate (1%)/
IODONIUM (1%)
(eta6-mesltylene) (etaS-cyclopentadlenyl) lron g mln
(l+) hexafluorophosphate (1%) (comparatlve)
IODONIUM (1%) (comparatlve) >20 mln
(etaS-cyclopentadlenyl)dlcarbonyl- 4-5 mln
trlphenylphosphlne lron (l+)
hexafluorophosphate (1%)/IODONIUM (1%)
(etaS-cyclopentadlenyl)dlcarbonyl- 10 mln
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trlphenylphosphlne iron (l+~
hexaflurophosphate (1%) (comparatlve)
The data of TABLE VII show that the two-component
curlng agent ls a more efflclent photolnltlatlon system than
comparatlve curlng agents.
EXAMPLE 8
A stock solutlon of 1.5 parts hexane dllsocyanate
and 3.5 parts poly(ethylene glycol) (molecular welght 400) was
prepared. To 1.0 g samples ln open vlals was added sufflclent
photocatalyst to reach the concentratlon shown
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in TABLE VIII below. Each sample was placed in a water
bath at 75C and irradiated using a Kodak Carousel
projector with a 360 nm cutoff filter. Cure times
(solidification times) are shown in TAsLE VIII.
s
TABLE VIII
Photocatalyst Cure Time
(eta6-mesitylene)(eta5-cyclopentadienyl)- 3 min
iron(1+) hexafluorophosphate
(1%)/IODONIUM (1%)
(eta6-mesitylene)(eta5-cyclopentadienyl)- 5 min
iron(1+) hexafluorophosphate (1%)
(comparative)
(eta5-cyclopentadienyl)dicarbonyl- 9 min
triphenylphosphineiron(1+)
hexafluorophosphate (1% )/IODONIUM (1%)
(eta5-cyclopentadienyl)dicarbonyl- 10 min
triphenylphosphineiron(1+)
hexafluorophosphate (1%) (comparative)
The data of TABLE VIII show that the two-component
curing agent is a more efficient photoinitiation system
than comparative curing agents.
Various modifications and alterations of this
invention will become apparent to those skilled in the art
without departing from the scope and spirit of this
invention, and it should be understood that this invention
is not to be unduly limited to the illustrative embodiments
set forth herein.
